• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.49 no.1
• /
• pp.13-18
• /
• 2000

We have fabricated LB ultra-thin films of maleate system by LB technique and evaluated the deposited status of LB ultra-thin films by I-V characteristics such as capacitance. It was found that the thickness of LB ultra-thin per layer is $27~30[{\AA}]$ by XRD. And, we have known that the conductivity along the horizontal direction of LB ultra-thin films was about $10^{-8}[S/cm]$, it corresponds to the semiconducting materials. Also, the I-V characteristics along the vertical direction of LB ultra-thin films was dominated by Schottky type current, the activation energy obtained by current-temperature characteristics was about 0.84[eV] and the conductivity was about $10^{-14}[S/cm]$, it corresponds to the insulator. And, the anisotropic conduction mechanism of the LB ultra-thin films in vertical direction and horizontal direction is determined by the hydrophilic group and the hydrophobic group in LB ultra-thin films. The above results are applicable to the semiconductor devices such as switching device, which function at the molecular level.

• Electric Engineers Magazine
• /
• v.228 no.8
• /
• pp.52-57
• /
• 2001

Presently the Korean grounding system uses TN system, multi-grounding method with IT independent grounding method. Nevertheless TN system can't exist with TT system in the technological terms. If they coexist, it causes ground-fault circuit not to operate, and brings about different electrical potential rise by customer system. It brings about serious problems for safety. This paper aims for improving method of grounding system based on the technical analysis on instances in foreign countries and Korea. Almost standards and construction manner were apt to be internationalized after WTO/TBT agreement was concluded. The internal grounding systems should meet the international criteria and reliability for safety, and be provided with technologically impeccable standards.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.48 no.9
• /
• pp.628-633
• /
• 1999

Degradation diagnosis of XLPE insulated URD cables was accomplished through out new method, which was to be analyzed by non-electrical experiments and synthesized by degradation points. To supplement this method, It was also carried out using several electrical analyses. Tan$\delta$ had commonly a different tendency by means oftemperature and frequency and also appeared higher at the outer part rather than innerpart of insulator. PD-q increased generally in proportion to the applied voltage andshowed regular patterns in relation to the thickness of insulator. Breakdown voltageswere measured and breakdown lifetimes were predicted appling for Weibull distribution function. As a result, breakdown lifetime in failure cables was shorter up to$\fraction one-third$ times than that in general cables. It was very available to estimate cable degradation using above method, but it needs further study on XLPE insulated URD cables in order to improve reliability.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.12
• /
• pp.2827-2835
• /
• 2010

When the inferiorthreshold potential is applied on the membrane, the resting status membrane does not display any specific reaction, in the meanwhile if it receives somewhat higher voltages then it shows entirely different configuration. The fact that there is this kind of characteristics on the exciting membrane has been known for a long time, and some researchers have tried to analyze this situation using the electrical circuits but only limitted to inferiorthreshold potential case. The quantitative studies of especially for transthreshold stimulus is extremely rare up to now. The direct application of electrical circuit to biostatus is somewhat uneasonable because there may be much differences between them. We studied the electrical reaction quantitatively of biomembrane when it receives the transthreshold stimulus in point of electricity in this paper.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.55 no.2
• /
• pp.82-87
• /
• 2006

Most of electric accidents are happened in the place where activities are frequent by common people who has low electric knowledge. Also, accidents are increased in the low voltage electric equipment. So, it is increased to spread the dispersion or non-utility power generation system. It means that ordinary times observation is required for electric equipments by common people. This paper is studied for the diagnosis method of electric equipment that common people can diagnose easily Voltage is generally and exactly measured in the electric and electronic field. We suggest new analysis tools using only electric voltage. It is called the Time-Energy analysis. The Time-Energy analysis is as following First, divide measured voltage waves into same parts, Second, conducted FFT(Fast Fourier Transform) transform for each divided period, Finally, each results are reassembled after graphic treatment. We compared Time-Energy analysis with discharge form by tracking tester. As the result, tracking discharge processes distinguished clearly.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.2 no.3
• /
• pp.17-22
• /
• 2009

The objective of this study was to develop a signal process software for a Electromyograph(EMG). And this paper was developed to general signal process software for a Electromyograph using biomechanics. It was used the clinic, rehabilitation, ergonomics and sports. It was composed to the module type for the monitoring frequency analysis, the zero crossing and comparison analysis etc. It's UI(User Interface) made up the continuous monitoring, the reports and the user-friendly-approach. This developed Electromyography will be applied to biomedical engineering system.

• Journal of Energy Engineering
• /
• v.24 no.1
• /
• pp.17-23
• /
• 2015

Electrical door system is one of the most essential items for the successful commercial operation of the railway vehicles. Nowadays, reliability values of electrical door system have a tendency to be included in technical requirements for design and manufacturing of rolling stocks. Manufacturer shall meet the reliability target values of electrical door system which is proposed by railway operator in procurement contract book. Railway operator shall approve the supplier's the reliability target values based on maintenance operation data. Railway operators are in the transition stage from the framework of maintenance interval based on time to the framework of maintenance interval based on distance. In this study, failure rates of the electrical door system currently used in railway vehicles are collected from maintenance field data. Failure rates are analyzed by using Minitab. Several kinds of plan for improving reliability are also suggested. It is necessary to keep studying on reliability prediction methodology, applying it in the field and implementing on improvement of reliability through feedback as well. Further, it will be useful for determining new maintenance policies or changing maintenance intervals for existing railway vehicles.

• The Journal of Korean Institute of Next Generation Computing
• /
• v.14 no.5
• /
• pp.7-18
• /
• 2018

Recently, serverless computing is spotlighted. Because it supports the development of application based on micro-service. Micro-service means a small-scale service that can operate independently. Applications with micro-service units have the advantage of enabling individual updates, easy and fast deployment. In addition, it has the advantage of supporting various languages and platforms for each service. Therefore many enterprise are trying to change from monolithic architecture to micro-service based architecture. However, there is a lack of research on methods and baseline for micro-service construction. In this paper, a method is proposed to construct the micro-service unit by analyzing UML design in monolithic application. It also shows the proposed approach can reconstruct monolithic application into micro-service based unit by implementing the constructed micro-services in a real serverless platform environment. In addition, the results of the comparative evaluation with the related studies are presented.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.1
• /
• pp.94-100
• /
• 2015

Coronal mass ejection (CME) released due to solar flare explosion cause geomagnetic disturbance. The induced current by massive geomagnetic disturbance can cause damage to the transformer. The calculated geoelectric field is a major parameter of the geomagnetically induced current (GIC). The method applying a Fourier transform has a high accuracy but it needs all data measured for 24 hours. And the other method applying a integral equation can calculate in real time but it requires to check an accuracy. To reduce the gap between the calculated results of two methods, it adjusts the integration section. As a result, the correlation between two calculated geoelectric fields is high, and the event time and direction of the calculated current is the same as that of the measured current, and it's accuracy rate is above 92 percent.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.18 no.6
• /
• pp.220-229
• /
• 2004

The AC railway system is quite differing from the general electric power system because it is single- phase and intermittently heavy loads. Thus, inevitably power quality problems are occurred in the AC railway system, i.e. voltage regulation voltage sags, voltage imbalance, and harmonic distortion. Recently, the power quality of the AC railway system becoming a hot issue because it is affect the control and safety of high-speed traction. In addition it is also affect the power quality of the electric power system. In this paper, single-phase Unified Power Quality Conditioner(UPQS) for the AC railway system is proposed to compensate the voltage sags and harmonic distortion. The configurations and control schemes of the proposed single-phase UPQC are presented. The effectiveness of the proposed single-phase UPQC application is verified by the PSCAD/EMTDC simulation works. It can be shown that the application of UPQC in the AC railway system is very useful to compensate the voltage sags and harmonic distortion from the results of related simulation works.